1. Field of the Invention
The present invention relates to a driving apparatus which utilizes an electro-mechanical conversion element such as a piezoelectric element.
2. Description of the Related Art
As the related-art driving apparatus which utilizes an electro-mechanical conversion element such as a piezoelectric element, as is described in the Japanese Patent No. 2633066, a driving apparatus is known in which a driving member (a drive rod) is caused to reciprocate in response to extension and contraction of an electro-mechanical conversion element (a piezoelectric element), so as to move a lens barrel which is frictionally engaged with the driving member along the driving member. In this driving apparatus, the driving member is attached to an end face of the electro-mechanical conversion element, and the driving member is provided continuously to and coaxially with the electro-mechanical conversion element.
However, since in the driving apparatus like this, the electro-mechanical conversion element and the driving member are continuously connected to each other and the driving member extends in the direction of extension and contraction of the electro-mechanical conversion element, it is difficult to reduce the size of the driving apparatus to a size which is equal to or shorter than a total length of the electro-mechanical conversion element and the driving member. In the event that the driving apparatus like this is attempted to be installed in small portable equipment such as a mobile phone for moving a photographic lens system, the driving apparatus is desirably made to be as small as possible. In particular, in order to reduce the thickness of the small portable equipment, the driving apparatus is desirably made to be short in the direction of extension and contraction of the electro-mechanical conversion element.